Abstract:
This study investigated and analysed facility soils and surrounding open field soils of different cropping years in Ningxia, with a view to investigating the effects of facility cultivation years on soil soil physicochemical properties.The results showed that, 1) the nitrate nitrogen of the facility soil was significantly higher than that of the open field soil, and the nitrate nitrogen of the soil in the cultivation layer was 4.28,6.78 and 12.6 times higher than that of the open field in the soil in the cultivation layer for >15 years, 10-15 years and <10 years, respectively, and the nitrate nitrogen of the upper layer under the facility cultivation was greater than that of the lower layer.Ammonium nitrogen was significantly higher in soils planted more than 15 years ago than in open field and soils planted less than 15 years; available phosphorus and available potassium contents of facility soils were 5-6 times and 1.0-2.5 times higher than those in open field, respectively.2) Facility soil pH was significantly lower than that of the open field, and pH decreased significantly at all levels as the number of years of planting increased; EC values were significantly higher in all three levels than in the open field.3) The water-soluble potassium and sodium ions of the facility soil were 6-13 times and 1-2 times higher than those of the open field, respectively, and both increased significantly with the increase of planting years.Calcium ion content was significantly higher than in the open field after >15 years of planting; magnesium ion content decreased with increasing years of planting.It could be seen that in China′s northern facility cultivation should be reasonable control of nitrogen, phosphorus, potassium fertiliser dosage, reasonable allocation of organic fertiliser and medium and trace elements fertiliser, to slow down the rate of degradation of the facility soil, to ensure that the facilities of agriculture, healthy and sustainable development.